<template>
  <div class="tagcloud-all" ref="tagcloudall">
    <a v-for="item in tagList" class="a"
       :href="item.url"
       rel="external nofollow"
       :style="'color:' + item.color + ';top: 0;left: 0;filter:none;'"
    >
      {{ item.name }}
    </a>
  </div>
</template>
<script>
export default {
  name: 'tagWall1',
  data() {
    return {
      tagList: [],
      // 直径
      radius: 100,
      dtr: Math.PI / 180,
      d: 300,
      mcList: [],
      active: false,
      lasta: 1,
      lastb: 1,
      distr: true,
      tspeed: 10,
      size: 150,
      mouseX: 0,
      mouseY: 0,
      howElliptical: 1,
      oList: null,
      oA: null,
      sa: 0,
      ca: 0,
      sb: 0,
      cb: 0,
      sc: 0,
      cc: 0
    }
  },

  methods: {
    // 生成随机数
    getRandomNum() {
      return Math.floor(Math.random() * (255 + 1))
    },

    // 三角函数角度计算
    sineCosine(a, b, c) {
      this.sa = Math.sin(a * this.dtr)
      this.ca = Math.cos(a * this.dtr)
      this.sb = Math.sin(b * this.dtr)
      this.cb = Math.cos(b * this.dtr)
      this.sc = Math.sin(c * this.dtr)
      this.cc = Math.cos(c * this.dtr)
    },

    // 设置初始定位
    positionAll() {
      this.$nextTick(() => {      // 注意: 所有的在onReady方法中执行的方法都需要$nextTick确保所有的标签都已经渲染
        var phi = 0
        var theta = 0
        var max = this.mcList.length
        var aTmp = []
        var oFragment = document.createDocumentFragment()
        // 随机排序
        for (let i = 0; i < this.tagList.length; i++) {
          aTmp.push(this.oA[i])
        }
        aTmp.sort(() => {
          return Math.random() < 0.5 ? 1 : -1
        })

        for (let i = 0; i < aTmp.length; i++) {
          oFragment.appendChild(aTmp[i])
        }

        this.oList.appendChild(oFragment)
        for (let i = 1; i < max + 1; i++) {
          if (this.distr) {
            phi = Math.acos(-1 + (2 * i - 1) / max)
            theta = Math.sqrt(max * Math.PI) * phi
          } else {
            phi = Math.random() * (Math.PI)
            theta = Math.random() * (2 * Math.PI)
          }

          // 坐标变换
          this.mcList[i - 1].cx = this.radius * Math.cos(theta) * Math.sin(phi)
          this.mcList[i - 1].cy = this.radius * Math.sin(theta) * Math.sin(phi)
          this.mcList[i - 1].cz = this.radius * Math.cos(phi)
          this.oA[i - 1].style.left = this.mcList[i - 1].cx + this.oList.offsetWidth / 2 - this.mcList[i - 1].offsetWidth / 2 + 'px'
          this.oA[i - 1].style.top = this.mcList[i - 1].cy + this.oList.offsetHeight / 2 - this.mcList[i - 1].offsetHeight / 2 + 'px'
        }
      })
    },

    // 坐标更新 让标签动起来
    update() {
      this.$nextTick(() => {           // 注意: 所有的在onReady方法中执行的方法都需要$nextTick确保所有的标签都已经渲染
        var a
        var b
        if (this.active) {
          a = (-Math.min(Math.max(-this.mouseY, -this.size), this.size) / this.radius) * this.tspeed
          b = (Math.min(Math.max(-this.mouseX, -this.size), this.size) / this.radius) * this.tspeed
        } else {
          a = this.lasta * 0.98
          b = this.lastb * 0.98
        }

        this.lasta = a
        this.lastb = b
        if (Math.abs(a) <= 0.01 && Math.abs(b) <= 0.01) {
          return
        }

        var c = 0
        this.sineCosine(a, b, c)
        for (var j = 0; j < this.mcList.length; j++) {
          var rx1 = this.mcList[j].cx
          var ry1 = this.mcList[j].cy * this.ca + this.mcList[j].cz * (-this.sa)
          var rz1 = this.mcList[j].cy * this.sa + this.mcList[j].cz * this.ca
          var rx2 = rx1 * this.cb + rz1 * this.sb
          var ry2 = ry1
          var rz2 = rx1 * (-this.sb) + rz1 * this.cb
          var rx3 = rx2 * this.cc + ry2 * (-this.sc)
          var ry3 = rx2 * this.sc + ry2 * this.cc
          var rz3 = rz2
          this.mcList[j].cx = rx3
          this.mcList[j].cy = ry3
          this.mcList[j].cz = rz3
          var per = this.d / (this.d + rz3)
          this.mcList[j].x = (this.howElliptical * rx3 * per) - (this.howElliptical * 2)
          this.mcList[j].y = ry3 * per
          this.mcList[j].scale = per
          this.mcList[j].alpha = per
          this.mcList[j].alpha = (this.mcList[j].alpha - 0.6) * (10 / 6)
        }

        this.doPosition()
        this.depthSort()
      })
    },

    doPosition() {
      this.$nextTick(() => {            // 注意: 所有的在onReady方法中执行的方法都需要$nextTick确保所有的标签都已经渲染
        var l = this.oList.offsetWidth / 2
        var t = this.oList.offsetHeight / 2
        for (var i = 0; i < this.mcList.length; i++) {
          this.oA[i].style.left = this.mcList[i].cx + l - this.mcList[i].offsetWidth / 2 + 'px'
          this.oA[i].style.top = this.mcList[i].cy + t - this.mcList[i].offsetHeight / 2 + 'px'
          this.oA[i].style.fontSize = Math.ceil(12 * this.mcList[i].scale / 2) + 8 + 'px'
          // this.oA[i].style.filter = "alpha(opacity=" + 100 * this.mcList[i].alpha + ")";
          this.oA[i].style.opacity = this.mcList[i].alpha
        }
      })
    },

    depthSort() {
      this.$nextTick(() => {            // 注意: 所有的在onReady方法中执行的方法都需要$nextTick确保所有的标签都已经渲染
        var aTmp = []
        for (let i = 0; i < this.oA.length; i++) {
          aTmp.push(this.oA[i])
        }

        aTmp.sort(function(vItem1, vItem2) {
          if (vItem1.cz > vItem2.cz) {
            return -1
          } else if (vItem1.cz < vItem2.cz) {
            return 1
          } else {
            return 0
          }
        })
        for (let i = 0; i < aTmp.length; i++) {
          aTmp[i].style.zIndex = i
        }
      })
    },

    // 网络请求 拿到tagList
    query() {
      // 假装从接口拿回来的数据
      let tagListOrg = []
      for (let i = 0; i < 17; i++) {
        tagListOrg.push(
          { name: '标签' + i, url: '' }
        )
      }

      // 给tagList添加随机颜色
      tagListOrg.forEach(item => {
        item.color = 'rgb(' + this.getRandomNum() + ',' + this.getRandomNum() + ',' + this.getRandomNum() + ')'
      })
      this.tagList = tagListOrg
      this.onReady()
    },

    // 生成标签云
    onReady() {
      this.$nextTick(() => {
        this.oList = this.$refs.tagcloudall
        this.oA = this.oList.getElementsByTagName('a')
        var oTag = null
        for (var i = 0; i < this.oA.length; i++) {
          oTag = {}
          oTag.offsetWidth = this.oA[i].offsetWidth
          oTag.offsetHeight = this.oA[i].offsetHeight
          this.mcList.push(oTag)
        }
        this.sineCosine(0, 0, 0)
        this.positionAll()
        this.oList.onmouseover = () => {
          this.active = true
        }
        this.oList.onmouseout = () => {
          this.active = false
        }
        this.oList.onmousemove = (event) => {
          var oEvent = window.event || event
          this.mouseX = oEvent.clientX - (this.oList.offsetLeft + this.oList.offsetWidth / 2)
          this.mouseY = oEvent.clientY - (this.oList.offsetTop + this.oList.offsetHeight / 2)
          this.mouseX /= 5
          this.mouseY /= 5
        }
        setInterval(() => {
          this.update()
        }, 30)            // 定时器执行 不能写setInterval(this.update(), 30)
      })
    }
  },
  created() {
    this.$nextTick(() => {
      this.query()
    })
  }

}
</script>

<style lang="css" scoped>
.tagcloud-all {
  position: relative;
}

a:hover {
  color: #FF0000;
  letter-spacing: 2px;
}

a {
  position: absolute;
  top: 0px;
  left: 0px;
  color: #fff;
  font-weight: bold;
  text-decoration: none;
  padding: 3px 6px;
}

</style>
